First question is actually a minor problem I have, I think the issues is the thermostat. It takes at least 20 minutes+ for my heater to even feel remotely warm in my truck. Would this be the thermostat or is it just the first gen 3.9's heated for ****? Also has anyone thrown a glasspack on the 91 or later 3.9 Dakotas? I'm curious if it sounds good or if I should just stick with my quiet muffler I have on there now.

 

it does sound like the thermostat .... and personaly i would not put a glass pack on the 3.9 keep it mild sounding

 

Does anyone suggest any kind of muffler to make a little more rumble for the 3.9 engine?

 

flowmaster 50 series, my friend has one on his 94' 3.9 v6, it sounds ok, but not anything like my 318. even with no muffler on the 3.9.

 

Like he said, exhaust on a 3.9 is nothing like the V8. Be preparred to lose all you low end power too. As for the heat, put a 180 degree thermostat in there in is should be good to go.

 

So you guys highly suggest not to put a glasspack on the 3.9?

 

I just put a 21" glass pack on my 92' Dakota 3.9 and cut the cat off. this little beast sounds almost like a 318, but not quiet as loud, and dont worry about losing any low end and if anything expect a little more throttle response and better fuel economy and a lot more noise. It doesn't sound loud in the cab if you run duels after the GP and run the pipe out the very back, but it does sound very nice and increases mpg.

 

I don't have an opinion on the glasspack. I have never used one myself. On the heater problem, the thermostat is a possible issue, as could be the heater core. Changing the thermostat is by far the easier and cheaper first fix. What does your temp gauge read? If you are able to determine that the thermostat is good or you replace it, then the likely culprit is the heater core.

 

i put a glass pack on mine a couple of years ago. sounds real good at idle, the only time i dont like it is when the rpm's get up there. i also cut out my cat and its dump at the rear end. my muffler was broke and didnt have the money to get a full set up so i just went with the glass pack. got a flow master now but im not gonna use till i get my 360 goin. havent notice any real power loss though.
i also had heating problems like yours, after i mopar warrantyed my first thermo. my heater works a little better but its still not all that great. at least im not totally frozen still by the time i get to work.

 

No it's not necessarily the tstat. If your Dak is overheating, then yes it would be the stat. If it is internal heat prob, it is more than likely the heater core or an air lock. It could be the stat stuck open if it is engine heat you're talking about. I would not recommend a 185 stat. Your truck is designed to operate best with a 195 degree stat. I would try stat first, don't forget a new gasket, all together usually less than $20.00. It would be easier to tell if you specified what kind of heat prob (in or out) your having.